Occurrence of Fusarium spp. associated with root tissues and rhizosphere soils of forest trees and assessment of their pathogenicity on Prunus amygdalus seedlings
Occurrence, distribution and pathogenicity of Fusarium spp. associated with roots and rhizosphere soils of forest trees were studied. Fusarium spp. was isolated from phloem and sapwood of forest trees and composite rhizosphere soil samples collected from highly diversified geographical and climatic regions of the west of Iran and identified based on their morphological characteristics. Only three Fusarium spp. (F. oxysporum, F. solani and F. eumartii) was isolated from roots. F. nygamai, F. graminearum, F. scirpi, F. proliferatum, F. anthophilum, F. longipes and F. chlamydosporum were recovered from soil samples collected from warm and moderately warm regions, while F. culmorum, F. sporotrichioides, F. sambucinum and F. subglutinans were recovered from cold regions. F. solani, F. oxysporum, F. semitectum, F. equiseti, F. verticillioides, F. merismoides and F. avenaceum were present in all climatic regions. In the bark inoculation tests, selected Fusarium strains representing all species were evaluated for their pathogenicity on stems of healthy Prunus amygdalus under greenhouse conditions. Stem rot assessment revealed that F. oxysporum, F. solani and F. eumartii were the most damaging species.